| 摘要 |
1279103 Automatic control LANDIS & GYR A G 26 Sept 1969 [30 Sept 1968] 47549/69 Heading G3R In an error-actuated closed-loop air-conditioning control system an error signal is applied both directly, and through a differentiator and a variable gain amplifier in cascade, to a PI controller. In Fig. 1, a signal X, corresponding to the value of a variable to be automatically controlled, is compared at 5 with a signal Rcorresponding to a desired value so that any error exceeding a predetermined value is effective through a three-point PD controller 12 and an integrator 4 to control the variable. The error signal 8 is combined at 7 with the error signal applied through a delay unit 6 to produce a differential control term which is added to the input of controller 12. The gain of an amplifier 3 is adjustable to an optimum value by an adjuster which, when the gain is a minimum, varies the gain of a feedback amplifier 15. In a modification, controller 12 is replaced by a two-point controller associated with a differentiator similar to unit 2. |
